This invention relates to a movement monitor suitable for detecting movement and is useful, although not restricted to, a movement monitor suitable for monitoring a human's or other living organism's breathing movement.
In considering the use of the movement monitor on human infants, it would be particularly useful for preventing Sudden Infant Death Syndrome (S.I.D.S.). S.I.D.S. is now the most common cause of death in industrialised countries among infants aged between one week to one year. The incidence of S.I.D.S. in the countries U.S.A., Great Britain, Canada and Australia are about 1.5 to 2 per thousand infants.
Despite the enormity of the problem, little progress has been made in the actual medical prevention of S.I.D.S. Moreover, because death usually occurs in apparently healthy infants without warning, much of the research work as to the cause of S.I.D.S. has to be done on post-mortem examinations or epidemiological speculations. Alternatively, many studies have been done on near miss S.I.D.S. or "high risk" infants, but unfortunately this group of subjects are not the same as the majority of S.I.D.S. patients who are usually healthy infants with no previous history of apnoea or like illness.
More widespread use of home apnoea or apnoea/bradycardia monitors may offer one hope of preventing S.I.D.S. It is believed that infants dying from S.I.D.S., may stop breathing for longer than thirty (30) seconds before death or irreversible brain damage, and intervention before this critical time may save their lives. It has also been observed that apnoea could be successfully terminated by stimulation.
Home monitoring programs exist in most countries that have a high incidence of S.I.D.S. However, because of the limitations in monitor design, the cost of running such programs, and the high manpower demand, these programs can only be employed for a limited number of selected "high risk" infants such as siblings from previous S.I.D.S. victims, infants with past history of Apnoea or Cyanosis, and cases of extreme prematurity. However, there is no existing monitoring program that caters for the normal, non high risk infants because of the shortcomings of existing monitoring systems.
At present there are four (4) popular types of monitors available to detect cessation of chest or abdominal movement. They are:
(i) The Graesby Dynamic MR 10 Respirator Monitor,
(ii) The Vickers Apnoea Alarm Mk 3,
(iii) Pressure sensitive pads placed underneath the infants,
(iv) Impedence systems
All of the above monitors are expensive and also very complicated to operate. All of the monitors require numerous tubes, conductors or sensors which are either attached to the infant, or to the mattress, from the main electronic monitoring unit. In the case where sensors need to be attached to the infant, problems are caused when the electrode becomes detached or where attachment causes local skin excoriation. Also, operating the monitors requires skill, and a great deal of training is needed before they can be operated accurately. Also, many of the various types of pressure sensitive pads are small, so that the infant may easily roll off the pads, thereby causing false alarms. Generally, such monitors are perceived as being either inaccurate, unreliable or insensitive.
Therefore, it is an object of this invention to provide a movement monitor that overcomes the above-mentioned problems, and provides a simple system for the general monitoring of movement.
It is a further object of this invention to provide a movement monitor that is suitable for use with an infant, simple to use, inexpensive to manufacture, and accurate in determining the breathing cessation.
Whereas problems exist in monitoring infants, it is also an object of this invention to provide a movement monitor suitable for use with adults or other respiring animals. Also, a person skilled in the art will readily recognise other areas where movement detection will be useful, such as providing an alarm when a machine or other moving device stops operating.